This invention relates to a drive aggregate for a heat pump and comprises a compressor as well as an internal combustion engine driving the compressor. The engine and the compressor are combined into a structural unit by means of a cylinder block which accommodates both the compressor cylinders and the engine cylinders and which also supports a common crankshaft by means of a plurality of bearings. The crankshaft is composed of a compressor-side crankshaft part and an engine-side crankshaft part which are secured to one another in axial alignment by interengaging end portions in the zone of a bearing common to both crankshaft parts. The common bearing is one of the two end bearings of the engine-side crankshaft part. The end bearing which is remote from the compressor side is designated as a first end bearing, whereas the end bearing adjoining the compressor side is designated as a second end bearing. With the engine-side crankshaft part there is associated at least one intermediate bearing which is situated between the two end bearings and which is a split bearing for permitting its lateral mounting on the engine-side crankshaft part.
A drive aggregate of the above-outlined type, in which thus the crankshaft is, for reasons of assembly, formed of two mutually relatively non-rotatable crankshaft parts, is disclosed in U.S. Pat. application by Hofbauer et al., Ser. No. 84,137 filed Oct. 12, 1979.